E30 Rear Spring Rates
E30 Rear Spring Rates
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Discussion

T89 Callan

Original Poster:

8,422 posts

217 months

Sunday 26th July 2009
quotequote all
The rear springs I recieved with my Supersport Kit are a bit long and soft to match the front so I was going to order some new ones from Faulkner (they cost about £20) probably something about 7' Long 1.9' id that I can drop onto the standard rear mounts.

Has anybody done this before and can anyone recomend a suitable spring rate (in lbs) as the Supersport ones don't come with any rate marked on them.

Car is a 1989 E30 320i Touring, that has been 'aggressively' stripped out, already has the uprated and shortened Supersport shocks at the rear and Supersport Coilovers at the front and will be used from track/drift work so comfort is irrelevant.

FYI this is why I need different rear springs.






Edited by T89 Callan on Sunday 26th July 03:18

handpaper

1,606 posts

227 months

Sunday 26th July 2009
quotequote all
If you're going to fit generic race springs of any size to the OE rear spring perch, I'd recommend fitting an adjustable adapter (H&R do one, among others) and probably a tender/helper spring, too.
Without this additional hardware you'll end up with either
a ) very little difference from standard (long, soft spring)
b ) firm springing, but sitting very high (long, stiff spring)
c ) firm spring and low ride height, but a good chance of the spring falling out when it becomes unloaded (short, stiff spring)

The OE rear spring is 245 lb/in (265 for M-Tech/Touring). For a dedicated track/drift car I'd start at 700 lb/in and work from there.

T89 Callan

Original Poster:

8,422 posts

217 months

Sunday 26th July 2009
quotequote all
handpaper said:
If you're going to fit generic race springs of any size to the OE rear spring perch, I'd recommend fitting an adjustable adapter (H&R do one, among others) and probably a tender/helper spring, too.
Without this additional hardware you'll end up with either
a ) very little difference from standard (long, soft spring)
b ) firm springing, but sitting very high (long, stiff spring)
c ) firm spring and low ride height, but a good chance of the spring falling out when it becomes unloaded (short, stiff spring)

The OE rear spring is 245 lb/in (265 for M-Tech/Touring). For a dedicated track/drift car I'd start at 700 lb/in and work from there.
Cheers for help.

I don't think they'll come out as the shortened shocks only allow about a 7" gap between the spring mounts on full droop anyway.

As it's so light at the back I may start with something around 500-600lbs.


T89 Callan

Original Poster:

8,422 posts

217 months

Monday 27th July 2009
quotequote all
Ordered some 51mm ID X 5" 650lb springs earlier today.

Should be Stiff with a capital STIFF!